Redskins quarterback Robert Griffin III drops back to pass during the first half against the Cowboys at FedExField. / Brad Mills, USA TODAY Sports

by Jarrett Bell, USA TODAY Sports

by Jarrett Bell, USA TODAY Sports

ASHBURN, Va. -- Robert Griffin III might not quite be himself again as he rebounds from a sprained lateral collateral ligament in his right knee. But at this point, with the Washington Redskins' phenomenal rookie quarterback set to make his first playoff start this weekend, there could be worse problems.

Griffin had his least-impressive passing game in Sunday night's NFC East title-clinching victory against the Dallas Cowboys, completing 9-of-18 passes for 100 yards. But gimpy knee and all, he still had impact with his legs by rushing for 63 yards on six carries.

"It's just not natural to go back and run a 4.3 40 (-yard dash)," Redskins coach Mike Shanahan said Monday. "It just doesn't happen. But when you're averaging over 10 yards a carry? That's still pretty good."

Cowboys linebacker DeMarcus Ware can vouch for that. Ware was frozen at the line of scrimmage on at least two glaring occasions, when Griffin faked option handoffs to Alfred Morris, then darted around the end for big gains. Late in the third quarter, Griffin's 10-yard scoring blast gave the Redskins (10-6) their first lead.

Two weeks after Griffin missed his only game this season, the knee held up. It marked further progress, even with the cutback moves a bit restricted as he wears a brace on the knee. A week earlier in his return at Philadelphia, he rushed just twice on scrambles. Yet his added work in the rushing game against the Cowboys -- complementing the 200-yard statement by Morris -- demonstrated that the Redskins were more comfortable using him on designed runs.

"Move the chains, that's all they asked me to do," Griffin said Sunday night. "They want me to be able to run that play to take some stress off the offensive line and some stress off of Alfred, even though he didn't look like he needed it. I was able to be effective; ran a touchdown, so that was awesome."

There were no setbacks with the knee, which is undoubtedly the best-case scenario heading into the playoff game at FedExField on Sunday, when Griffin will be matched against another dazzling rookie quarterback, the Seattle Seahawks' Russell Wilson.

Don't expect Griffin to resemble his pre-injury form yet. But as he has demonstrated in the last two games, he can compensate well enough to win.

"The LCL is going to take some time," Shanahan said. "We all know that. Is it a month? Is it a month and a half? You never know if it's completely healed. Is he 4.5, 4.4? I don't know. The doctors say he's 100%."

Shanahan says he has been encouraged by Griffin's practice work over the last two weeks, when he has fully participated in drills. He says he's not concerned that Griffin is at risk for further damage.

"We don't have to worry about him reinjuring that LCL. The brace helps him, at least mentally, knowing that he's not putting too much pressure on it. Sometimes, that's why he looks a little different when he does cut. It bothers him just a hair. But it's something he has to wear. Hopefully it gets better and better."